I installed a clean version of Windows 10 and Visual Studio 2015. I checked out my project from Visual Studio Team Services (was TFS Online) and built it. Ok! Then I went to run it and got this message when I hit a page that called the database.

I see the db was created by Entity Framework and my tables are there (when looking at SQL Server Object Explorer) in VS. But I'm a little confused as to why it's asking me to update the db, I haven't changed any thing since EF created it.

Now execute "update-database" command from package manager console and it will create database for you without any obstacles.

If you are using SQL LocalDb, don’t ever delete the physical .mdf and .log files for your database without going through the SQL Server Object Explorer in Visual Studio or in SQL Server Management Studio. If you delete the files only, you end up with an error like mentioned above.

Solution 2

May be your App_Data folder is empty? When you opened up the App_Data folder, you found an empty folder? It seems like you have to create the database file yourself. Opened up the solution, right clicked on the App_Data folder and choose Add –> New item->Create SQL Server Database…
or get a file from the TFS -> Source Control Explorer